Rung and side rail connection for ladders



Sept. 28, 1965 H. s. ARNOLD HUNG AND SIDE RAIL CONNECTION FOR LADDERSFiled Dec. 2, 1963 INVENTOR. HAROLD G. ARNOLD AT T YS.

United States Patent 3,208,554 RUNG AND SIDE RAIL CONNECTION FOR LADDERSHarold G. Arnold, Wooster, Ohio, assignor to The Bauer ManufacturingCompany,

6 Claims. (Cl. 182-46) This invent-ion relates to ladders having hollowside rails made of impregnated fiberglass and means for attaching rungsthereto, particularly whereby the attachment is made without deformingeither the rung or the side rail.

This application is an improvement to my co-pending patent applicationSerial No. 153,985 on Rung and Side Rail Connect-ion for Ladders filedon November 21, 1961, and now abandoned. These applications have beenfiled because in recent years conventional wooden ladders have, to atleast some extent, been replaced with ladders having portions thereof,and usually side rails, made of aluminum or its alloys. Ladders of thistype are often more durable and stronger than wooden ladders, but areopen to the objection that they will conduct electricity which isundesirable in many uses of a ladder. Further, fiberglass can provideeven greater durability and strength than aluminum.

Therefore, it is the general object of the invention to avoid andovercome the foregoing and other difiiculties of and objections to priorart practices by the provisions of a ladder in which the side rails aremade of hollow, resin impregnated fiberglass, and which is characterizedby simplicity of construction, lightweight and high strength in use, anda long and maintenance-free life.

Amother object of the invention is to provide a ladder having hollowresin impregnated fiberglass side rails oined together with a pluralityof rungs the ends of which abut against the side rails and which areheld in position there-against by bolt means engaging sleeves whichengage the outer surface of the fiberglass side rail with the thrust ofthe bolt being taken against spools positioned around the bolt meansinside of each side rail. The aforesaid objects of the invention, andother obects which will become apparent as the description proceeds, areachieved by the combination in a ladder of a pair of hollow fiberglassside rails, a plurality of sleeves having one enlarged end slidablypositioned through opposed holes in the side rails at equally spaceddistances so that enlarged ends abut one side of the side rails and theother ends protrude from the othre side thereof, fiberglass rung meansadapted to be slidably positioned over the protruding ends of thesleeves between the side rails, support means inside the side railsadapted to support the area adajacent to the opposed holes, and means tooperatively engage the rungs to their respective sleeves.

For a better understanding of the invention reference should be had tothe accompanying drawings, wherein:

FIGURE 1 is a front elevation, partly broken away, of a ladderconstruction incorporating the principles of the invention; and

FIGURE 2 is a slightly enlarged cross-sectional view taken substantiallyon line 22 of FIGURE 1.

In the drawings, the numeral 10 indicates generally a ladder having apair of side rails 12 made of resin-impregnated fiberglass and having ahollow elliptical shape in cross section, as more particularly seen inFIGURE 2. Each side rail 12 has a hollow substantially elliptical shapein cross section to provide a structural relationship which is light inweight but of very high strength. The substantially elliptical shape ofeach side rail provides opposed side wall portions 14 which areessentially parallel, and which are formed with opposed openings 16,

Patented Sept. 28, 1965 usually circular, to slidably receive the endsof sleeves, indicated generally by numeral 18. The sleeves 18 have anenlarged head portion 20 adapted to abut against the outer side wall 14and an extended end portion 22 which is adapted to protrudesubstantially normal to the side rail 12 a distance equal to at leastthe thickness of the side rail 12. The sleeves 18 also contain alongitudinally axially aligned hole 24 adapted to receive a bolt 26 tohold the sleeves 18 in position, as will be more fully describedhereinafter. Further, in order to protect and strengthen the enlargedend 20 and the hole 24, each sleeve 18 may have a strengthening metalcollar 28 integrally formed therewith during the molding operation.

The protruding ends 22 of the sleeves 18 are adapted to slidably receivethe ends of rungs 30. The rungs 30 are normally made of hollowrelatively thin-walled fiberglass or plastic tubing with the sleeves 18being equally spaced vertically on the side rails 12 so that the rungs18 lie in substantially horizontal parallel relationship to each otherin the normal ladder configuration. The open ends of the rungs 31 areadapted to abut against the outer surface of the inner side wall 14. Itis contemplated that the bolt 26 will extend axially through the rungs30 to a similar sleeve rung combination on the opposite side rail sothat a nut (not shown) can be tightened on the end to draw the opposedsleeves 18 towards each other forcing the rungs 30 into the side walls14 and providing a very secure rung side wall combintion.

In order to prevent dishing or bending of the side walls 14 when thebolt 26 is tightened, as described above, a spool-like member 32 isprovided to surround the end of each sleeve 18 inside of each side rail12. The spool-like member 24 is usually of metal and formed with flanges34 which engage the inside surfaces of the side walls 14 of the siderail 12. Thus, the force of the screw 26 being tightened which urges thesleeves 18 towards each other is taken up by the spool-lik member 24 toinsure a firm seating of the rungs 30 to provide a particularly strongand rigid construction, all without dishing inwardly the side walls 14of the side rails 12.

Thus, it is seen that the entire outward construction of the ladder isfiberglass or plastic to prevent any possible electric conduction or toprevent rusting and metal deterioration. A plastic plug 40 may bepositioned over the head of the bolt 26 to insure that this metalsurface is insulated and protected. The invention further contemplatesthat epoxy cement or other suitable adhesive might be used between theextended portion 22 of the sleeve 18 and the ladder rung 30 and vfurtherbetween the enlarged head 20 of the sleeve 18 and the outside of theside wall 14 to more securely position the assembled combination.

The invention further contemplates that the spool-like member 32 may bemade of rigid reinforced plastic with a greater thickness or that otherreinforcing means he provided for the area adjacent the holes 16.Further, nut means could be operatively carried by the rungs 30 so thatthe bolts 26 might be screwed thereinto to properly seat the rung 3t andthe sleeve 18 into position, rat-her than having the bolt 26 extendcompletely through the rung. However, with the bolt 26 extending throughthe rung a safety feature is provided since this bolt will provide abackup if the rung 30 breaks because of excessive pressure.

One of the problems encountered in a ladder construction of the typedescribed above is positioning the spoollike members 32 in'the siderails 12 so they are aligned with their respective opposed openings 16.Various means are available to achieve the positioning of the spool-likemembers 32 such as utilizing a notched steel beam having movable fingersholding the spool-like members in the notches with the beam beinginserted inside the hollow side rail to properly position the spool-likemembers, After the spool-like members are positioned, the fingers wouldbe releasable allowing the beam to be withdrawn from the side rail.Another approach would be to place the spool-like members in theirproperly spaced relationship on an adhesive masking tape which had beenpreviously punched. The adhesive surface of the tape would hold thespools in place, and the tape could be pulled into the side rail to therequired length to properly position the spool-like members. The maskingtape would be left in the side rails permanently after the rungs werepositioned in combination with the side rail. One more approach might beto mount the spoollike members on a cardboard strip at the same equallyspaced distances as the rungs so that the cardboard strip could bepulled inside the side rails to position the spoollike members and thenremain inside the side rail after assembly of the rungs to complete theladder. Thus, it is seen that the problem of placing the spool-likemembers in proper position inside the side rails is overcome.

While in accordance with the Patent Statutes only one best knownembodiment of the invention has been illustrated and described indetail, it is to be particularly understood that the invention is notlimited thereto or thereby, but that the inventive scope is defined inthe appended claims.

What is claimed is:

1. In a ladder the combination of a pair of fiberglass side rails, saidrails having a hollow cross section providing side walls havingsubstantially parallel opposed portions,

a plurality of hollow substantially cylindrical fiberglass rungs havingopen ends operatively positioned between the side rails andsubstantially aligned with opposed openings in the side walls of therails,

a plurality of sleeves each having one enlarged end slidably received inclose spaced relationship through said opposed openings and into theopen ends of said rungs so that said enlarged ends engage the outersurface of said side rails opposite to said rungs,

a spool slidably received on said sleeves inside each side rail andengaging the inside surface of the side walls of each side rail, and

bolt means operatively received through and adapted to engage opposingsleeves, and passing longitudinally through the operatively positionedrung to bias said sleeves together and hold the rungs in position on theside rails.

2. In a ladder the combination of a pair of hollow side rails havingopposed side walls,

a plurality of sleeves each having one enlarged end slidably received inclose fitting relation through opposed openings in said side rails sothat the enlarged ends abut against one side of the side rails and theother end protrudes a distance from the opposite side thereof,

a plurality of hollow rungs with opened ends slidably positioned overthe protruding ends of said sleeves between said side rails and abuttingagainst the opposed opposite sides thereof,

collar means slidably positioned over said sleeve means inside said siderails and adapted to engage the inside surfaces of said side walls, and

tie rod means extending through each rung to connect opposed sleevessupporting the rung.

3. In a ladder the combination of a pair of hollow fiberglass side railshaving opposed walls,

a plurality of sleeves made from a hard plastic material each having acontinuous uniform cylindrical shape and one enlarged end reinforcedwith a metallic insert, said sleeves slidably received in close spacedrelationship through opposed openings in said side rails so that theenlarged ends abut against one side of the side rails and the other endprotrudes a distance from the opposite side,

a plurality of hollow fiberglass rungs with opened ends between saidside rails positioned slidably in close spaced relationship over theprotruding ends of said sleeves to about the inner sides of the siderails, and

bolt means to operatively position the sleeves in pressured relationshiptoward each other to hold the rungs firmly in position adjacent the sidewalls of said side rails.

4. In a ladder, hollow side rails each having opposed parallel Walls,hollow rungs extending between and abutting the inner sides of the siderails, a collar positioned between the parallel walls of each side railin a position where the axes of the collar and the associated rung arecoincident and the ends of the collar bear against the opposed parallelwalls of the side rails, means having a continuous uniform cylindricalshape extending through aligned holes in each side rail and into the endof each rung adjacent the side rail, a shoulder on the outer end of thelast-named means, and means pressing the shoulder against one wall ofthe side rail, pressing the rung against the other wall of the siderail, and pressing the walls of the side rail against the ends of thecollar.

5. In a ladder the combination of a pair of hollow fiberglass siderails,

a plurality of sleeves having one enlarged end and the remaining lengthof a continuous uniform cylindrical shape slidably positioned throughopposed holes in said side rails at equally spaced distances so thatsaid enlarged ends abut one side of the side rails and the other endsprotrude from the other side,

fiberglass rung means adapted to be positioned between said side railsslidably in close fitting relationship over said protruding ends of saidequally spaced sleeves to abut the inner sides of the side rails,

support means inside the side rails adapted to support the area adjacentto said opposed holes, and

bolt means adapted to operatively engage the sleeves supporting oppositeends of each rung to urge them together to hold the ends of the rungs inpressured adjacent relationship with respect to the side rails.

6. In a ladder the combination of a pair of hollow fiberglass side railshaving opposed side walls,

a plurality of sleeves each having an enlarged head at one end, and theremaining length of a continuous uniform cross sectional cylindricalshape, said sleeves slidably received through opposed openings in saidside rails so that the enlarged heads abut against the outside of oneside wall of the side rails and the other end protrudes outwardly fromthe other side of the side rails,

a plurality of hollow fiberglass rungs with opened ends positionedbetween said side rails slidably in close spaced relationship over theprotruding ends of said sleeves to abut against the inner sides of theside walls, and

means to bias opposed sleeves supporting each rung towards each other.

References Cited by the Examiner UNITED STATES PATENTS 1,136,010 4/15Hendricks et al 182-216 3,008,552 11/61 Cushman et al. 182228 3,101,2058/63 Benharn 2 87-2O FOREIGN PATENTS 1,036,119 4/53 France.

657,746 9/51 Great Britain. 870,536 6/ 61 Great Britain.

HARRISON R. MOSELEY, Primary Examiner.

REINALDO P. MACHADO, Examiner.

5. IN A LADDER THE COMBINATION OF A PAIR OF HOLLOW FIBERGLASS SIDERAILS, A PLURALITY OF SLEEVES HAVING ONE ENLARGED END AND THE REMAININGLENGTH OF A CONTINUOUS UNIFORM CYLINDRICAL SHAPED SLIDABLY POSITIONEDTHROUGH OPPOSED HOLES IN SAID SIDE RAILS AT EQUALLY SPACED DISTANCES SOTHAT SAID ENLARGED ENDS ABUT ONE SIDE OF THE SIDE RAILS AND THE OTHERENDS PROTRUDE FROM THE OTHER SIDE, FIBERGLASS RUNG MEANS ADAPTED TO BEPOSITIONED BETWEEN SAID SIDE RAILS SLIDABLY IN CLOSE FITTINGREALTIONSHIP OVER SAID PROTRUDING ENDS OF SAID EQUALLY SPACED SLEEVES TOABUT THE INNER SIDES OF THE SIDE RAILS, SUPPORT MEANS INSIDE THE SIDERAILS ADAPTED TO SUPPORT THE AREA ADJACENT TO SAID OPPOSED HOLES, ANDBOLT MEANS ADAPTED TO OPERATIVELY ENGAGE THE SLEEVES SUPPORTING OPPOSITEENDS OF EACH RUNG TO URGE THEM TOGETHER TO HOLD THE ENDS OF THE RUNGS INPRESSURED ADJACENT RELATIONSHIP WITH RESPECT TO THE SIDE RAILS.